Multi-objective optimization of the oil-free centrifugal air compressor in hydrogen fuel cell vehicles based on grey relational analysis

Centrifugal air compressor is critical to hydrogen fuel cell vehicles due to it guarantees the air provided to the stack is higher pressure ratios and a larger flow rate. However, the compressor has low efficiency and high energy consumption. In this paper, the multi-objective optimization was performed based on experimental data, which considered both the maximum isentropic efficiency and minimum total power consumption. The effects of the factors on the performance of the compressor were obtained by mean S/N ratios. The contributions of the factors to the optimization objectives of the compressor were investigated by analysis of variance. The optimal parameters combination providing the larger isentropic efficiency and lower total power consumption was found by grey relational analysis. The isentropic efficiency increased by 34.5% and total power consumption decreased by 48.5% in comparison with the average value in all Taguchi cases for the optimal compressor.